The present invention relates to a component connecting apparatus and method for connecting a component to a board by use of a heating device and a component mounting apparatus provided with the component connecting apparatus and relates, in particular, to a component connecting apparatus and method for connecting a small-sized low-profile component, that partially has a weak heat-resistant portion of a low heat-resisting property, to a board, and a component mounting apparatus.
Regarding conventional component mounting, an electronic component (a component) to be mounted onto a circuit board (a board) has an electrode connection portion, that is a portion to be connected to an electrode portion of the circuit board, and a component body portion that carries a function of the electronic component. Regarding such electronic component, mounting of the electronic component onto the circuit board is performed by forming and arranging a solder portion of solder or the like, which is a connecting material, between the electrode portion of the circuit board and the electrode connection portion of the electronic component, mounting the electronic component onto the circuit board via the solder portion, thereafter heat-fusing the solder portion and subsequently cooling and solidifying the solder portion.
However, in general, the component body portion of the electronic component often has a lower heat-resisting property than that of the electrode connection portion. If heat in heat-fusing the solder portion is conducted also to the component body portion and a temperature of the component body portion becomes higher than its heatproof temperature, then the component body portion suffers thermal damage, and the electronic component is disadvantageously thermally damaged.
In order to prevent occurrence of the aforementioned problem, with regard to the conventional component mounting, there have been invented apparatuses such that a temperature rise of the component body portion is restrained by removing conducted heat by, for example, blowing a cold blast against the component body portion, and its neighborhood, of the electronic component by a cold blast nozzle concurrently with blowing a hot blast against the electrode connection portion, and its neighborhood, of the electronic component by a hot blast nozzle for heat-fusing of the solder portion (refer to, for example, Japanese unexamined patent publication Nos. H10-51133, H6-151032, H9-283913 or 2002-16352).
Moreover, electronic components have conventionally been mounted on a flexible board (FPC (Flexible Printed Circuit Board)) in order to execute display control of an LCD section and perform electrical connection between an LCD module and a mother board in an LCD module used for a mobile device or the like. A driver IC for display control and chip components of capacitors, and the like, are mounted on this FPC. A connection portion of the driver IC has a narrow pitch, and contamination of the connection portion becomes a cause for degrading reliability of the LCD module. Therefore, the driver IC is normally mounted before mounting of the chip components.
After mounting of the driver IC, as shown in FIG. 28, solder is fed onto the FPC by a solder printer 501 that feeds solder to the FPC, and a chip component is placed on the FPC by a component mounter 502. Then, this resulting FPC is conveyed into a reflow apparatus 503 that has a heat source for fusing the solder, and the solder is fused to connect the chip component to the FPC. In this case, this circuit board can also be conveyed by a belt conveyer if its thickness is about 1 mm and has rigidity. However, in case of a flexible film-shaped circuit board of, for example, the aforementioned FPC, as shown in FIG. 29, there is adopted a method for aligning and fixing FPC's 505 on a pallet 504 and conveying the FPC's 505 into the reflow apparatus 503. In this case, the reflow apparatus 503 is a reflow apparatus that heats atmosphere inside a furnace and performs collective connection of the FPC's 505 on the pallet 504 with solder.
Moreover, when FPC's 505 of different types are produced, the FPC's 505, on which components corresponding to the types are mounted, are conveyed. In this case, productivity is poor with a reflow apparatus that heats an atmosphere inside a furnace, and it is more efficient to heat only required portions. Therefore, a reflow apparatus of local heating with a light beam system as shown in FIG. 30 is effective. In particular, to prevent light from being applied to portions other than the required portions, it is effective to apply light emitted from a light emitting section 511 to the required portions through an opening 513 of a mask 512. It is to be noted that reference numerals 506, 507 and 508 denote a chip component, IC and solder, respectively, in FIG. 30.
When FPC's 505 of the same type are mass-produced, productivity is rather improved by arranging the FPC's 505 on a largest possible pallet 504 and performing connection with solder at a stroke. However, it has recently been often a case where there is insufficient time for processes from determination of specifications of a circuit board to production due to short product life, diversification of models, complication of design ascribed to advanced functions and flowability of market trend. Accordingly, it has become difficult to increase production efficiency by a mass-production method with the large pallet 504.
Moreover, a production facility as shown in FIG. 28 is originally intended for processing large-size boards, and therefore, an apparatus itself is large. Particularly, the reflow apparatus, which heats the atmosphere inside the furnace, generally has a length of 3 to 5 m for soak heating. Equipment is extremely large with respect to a size of a circuit board that has a size of about 2 to 30 mm, and it is difficult to take flexible measures. It is to be noted that a system equipped with the solder printer 501, the component mounter 502 and the reflow apparatus 503 shown in FIG. 28 has a total length extended up to, for example, 7 m.
Moreover, although the light beam system is effective in a case of same components and a small amount of components, it is a recent tendency that an amount and types of chip components 506 on FPC 505 are increasing in accordance with functional advancement of an LCD module. When components of different light absorption coefficients exist on the FPC 505, a setting of light application conditions and the like becomes difficult. For example, it is one method to control conditions by the mask 512 for, for example, black electronic components and weak heat-resistant electronic components. However, there is a limitation in coping with each individual component only with the mask 512 because of a possible occurrence of a semi-fused state of adjacent solder.
On the other hand, in order to cope with the aforementioned problems, there has been invented a apparatus that performs heat-fusing of solder by providing a heating device for a stage on which a circuit board is placed instead of heating an atmosphere around the circuit board and heating the circuit board via the stage (refer to, for example, Japanese unexamined patent publication No. 2002-151553). In such apparatus, the circuit board is directly heated instead of heating the atmosphere around the circuit board, and therefore, energy necessary for heating by the apparatus can be more efficiently used for heat-fusing of solder.